1. Field of the Invention
This invention relates to fireplaces and specifically to coal burning fireplaces functioning as furnaces to completely heat a structure's interior and provide domestic hot water.
2. Prior Art
Fireplaces for providing heat to the interior of living quarters have been around for innumerable years. They have evolved from simple pits in the earth to attractive brick structures which complement the decor of modern homes. Prior art fireplaces generally include a brick hearth for burning wood therein. The burning area is usually closed off from the house interior by a screen or glass doors. Exhaust gasses are vented through the roof of the structure by a chimney. Generally prior art fireplaces are more desirable to the homeowner for their aesthetic value than for heating. Not only does the interior brick work of the hearth add a rustic beauty to the interior but a crackling fire provides the residents with a sense of serenity and security.
Most prior art fireplaces are inefficient heat sources. Modern day homes do not rely exclusively on the heat generated by a fireplace but instead have alternately fueled e.g., gas, electricity or oil systems which meet the heating requirements of the structure. The fire in the fireplace requires oxygen for continued combustion. The combustion supporting oxygen is drawn from the air within the interior's structure. This air is warm relative to the exterior air. The relatively warm air is used in the combustion of, for instance, the logs in the fireplace and vented to the atmosphere through the chimney as exhaust gas. In order to maintain an air pressure equilibrium between the interior air pressure and outside atmospheric pressure, the exhausted interior air must be replaced. Replacement air enters the structure from cracks around, for example, doors and windows, in the foundation, and through exhaust vents, etc. The replacement air entering is relatively cold compared to the interior air, sometimes more than 70.degree. F. colder. The structure's main heating system must work excessively hard to heat the entering cold air. The heat radiated from the fireplace is sufficient to thoroughly heat the room adjacent the fireplace but insufficient to properly heat rooms remote from the fireplace which may be experiencing a great influx of cold air.
Most prior art fireplaces are not designed for use with coal. As compared to wood, coal requires a hotter ignition flame and more oxygen for proper combustion. It would be exceptionally difficult to maintain coal combustion in many prior art fireplaces. Homeowners are restricted to burning wood in their fireplaces. This is unfortunate since coal is a more efficient, cost-effective fuel than wood. Furthermore, anthracite coal, for instance, is plentiful and clean burning.
Prior art fireplaces include, for example, that disclosed in U.S. Pat. No. 1,013,372--Brandes. Brandes discloses a fireplace heater for heating a plurality of rooms.
U.S. Pat. No. 1,681,995--Miles discloses a heater of the fireplace-type which can heat a plurality of rooms. Additional room heating is accomplished by placing return air flues in the rooms to be heated which communicate with the air compartment of the fireplace. Humidity supplying water pans are also disclosed.
U.S. Pat. No. 1,722,560--Cornelius discloses a circulating system for a fireplace for heating rooms remote from the fireplace location. The fireplace draws air from a room adjacent the fireplace and delivers it by ducts to the remote location. An air forcing apparatus such as a fan, is disclosed for delivery of the heated air. Ducts are provided for admitting combustion air beneath the fire.
U.S. Pat. No. 2,052,643--Modine discloses a device for withdrawing air from a room into an adjacent fireplace where it is heated and discharged back into the room under forced draft.
U.S. Pat. No. 2,077,599--Wales discloses a heating system which uses a fireplace as the lone heat source. A blower is used for forced air distribution. The blower is controlled by a thermostat for proper heat regulation.
U.S. Pat. No. 2,151,016--Donley discloses a fireplace with relatively cool air inlets near the foot of the fireplace and heated air outlets at higher points.
U.S. Pat. No. 2,181,624--Maurer shows a forced air fireplace heater generally serviceable from a rear service area. Water-containing plans for supplying humidity to the heated air are included. An ash pit is also disclosed for accumulating the by-products of burning.
U.S. Pat. No. 2,231,258--Elmore discloses a heating system for a conventional fireplace. Forced air return ducts and a blower are disclosed for returning relatively cool air to the fireplace from remote locations for reheating. The reference further discloses ducts for the distribution of heated air to plural, remote rooms.
U.S. Pat. No. 2,296,354--Kraus discloses a forced air fireplace having a thermostatically controlled blower motor. Air is withdrawn from the room adjacent the fireplace, heated and recirculated back to the room. A water pan for providing humidifying water is included.
U.S. Pat. No. 2,497,468--Barber discloses a fireplace having forced draft air conduits communicating with the basement or exterior for providing fresh combustion air to the fire. The reference discloses valves for controlling the amount of draft.
U.S. Pat. No. 3,721,225--Tidwell discloses a pre-fabricated fireplace suited for assembling at the job site.
U.S. Pat. No. 3,773,029--Kent discloses a fireplace damper control operable from the front facing of the fireplace.
U.S. Pat. No. 3,880,142--Fowles discloses a push-pull fireplace damper opening mechanism operable from outside the fireplace.
U.S. Pat. No. 4,026,263--Boyd discloses a fireplace system having a firebox and air supply means for warmed air circulation within the house as well as for providing combustion air to the fire. A thermostat can control the amount of warmed air circulated and/or combustion air supplied.
U.S. Pat. No. 4,062,344--Mayes discloses a fireplace heating system including heating ducts to heat a plurality of rooms and a front mounted damper control.
U.S. Pat. No. 4,180,052--Henderson discloses a fireplace furnace with forced combustion air means, and lower mounted front warm air vents. The system includes a water heater.
U.S. Pat. No. 4,223,833--Ebbers discloses a fireplace unit including a firebox, outside air intake means and forced air heating means.
U.S. Pat. No. 4,274 393--Scaran discloses an insert for an existing fireplace structure having water troughs for supplying humidity to the heated air.
U.S. Pat. No. 4,336,790--Bartsch discloses which can be constructed in place or pre-fabricated which has a blower forcing cool outside air into the firebox where it is heated and emitted into the adjacent room. A pipe delivers water mist to the forced air ducts to maintain sufficient moisture in the heated air. Water circulating and heating apparatus is further shown whereby the fireplace can heat large quantities of water.
U.S. Pat. No. 4,403,573--Cauchy discloses a water heating apparatus attachable to a firebox which stores heated water in a tempering tank.
U.S. Pat. No. 4,426,994--Burger et al. discloses a fireplace having combustion and heating air ducting as well as water heating means.
U.S. Pats. Nos. 4,438,755 and 4,612,878--Moffett and Schnurer each disclose wood burning stoves that heat and circulate water.
Whereas a number of prior art references disclose various means and features to improve the efficiency and usefulness of fireplaces, none disclose a comprehensive, primarily coal burning furnace system which meets all heating needs including heating water for domestic use.
The invention as herein provided goes beyond all prior art fireplaces to disclose a complete home air and water heating system, that may be fueled with coal and that is easily and completely controllable, efficient and maintainable. The invention provides a complete coal burning heating system. No other alternately powered systems are necessary to heat and supply hot water to an average to large sized family home or similarly sized structure. Since coal is readily available domestically, the user of this system can be unconcerned with unstable foreign oil supplies and prices.